The present invention relates generally to carrying cases and more particularly to a carrying case which may be made of conventional materials so as to be suitable for use in carrying various articles or which may be made substantially of antistatic materials so as to be particularly suitable for use in carrying articles which are sensitive to discharges of static electricity.
It is generally desirable that carrying cases be relatively light in weight to facilitate handling, as well as strong and durable. U.S. Pat. No. 3,259,217 to Platt discloses a carrying case which has proven successful in providing these features. This case includes a pair of spaced rigid end shells having peripheral flanges forming inwardly facing opposed grooves or channels. A unitary member including a bottom wall and a pair of side walls interconnects the end shells with its opposite ends extending into the inwardly facing channels of the end shells. A pair of overlapping lid pieces extend longitudinally of the side walls and are pivotally secured thereto.
U.S. Pat. No. 4,374,555 and co-pending application Ser. No. 468,575 entitled "Carrying Case" disclose carrying cases which also employ opposed molded end shells interconnected by a unitary member. While the use of such molded end shells provides many advantages over various other possible constructions, it may be desirable to construct a case having end members which are not readily moldable into shapes which provide the desired features or which are relatively expensive to mold into such shapes.
For example, antistatic materials which have been found to be useful in packaging certain types of items present greater difficulty in molding than materials which have generally been used in the past to form the end shells of the above-referenced cases. Antistatic materials have electrical properties which inhibit or prevent rapid discharge of static electricity, and are used in packaging of items such as sensitive electronic components which are subject to damage by static electricity. One such material is a transparent polyethylene sold by Richmond Division of Dixico Incorporated under the registered trademark RCAS 1200.
One of the problems addressed by the present invention reates to providing a carrying case which includes some of the proven structural features of the above-referenced cases and which may be made without molded end shells so that any of various different materials may be used in constructing the ends of the case.